Hedges of Troyes Champagne Métropole

**Definition**:
Axis of a hedge.
The hedge is defined as a natural fence made up of trees, shrubs, thorns or branches and used to delimit or protect a field.

**Selection**:
This layer of linear hedgerows is the result of the combination of the surface hedgerows of the Zone de végétation layer of the BDTopo®, Nature = "Hedge", and the surface hedgerows from the Register Parcellaire Graphique (RPG), a combination followed by skeletonisation.

• The (surface) hedges of the BDTopo® Vegetation Zone layer are seized at the edge of the crown. Their width must be less than 20 m, and their length more than 25 m. The cut-off threshold for seizure is 20 m. Refer to the definition of Nature="Hedge" in the Vegetation Zone class.
• The (surface) hedges of the GPR are seized according to the ground right-of-way. The width of the crown of the modelled hedge shall be less than 20 m, and their minimum length shall be a few metres (requirement for the object to be long).

The cut-off point for seizure is 5 m.

**Geometric modelling**:
Line joining the crown of the first tree to that of the last.
These hedges, resulting from the merger of these two sources, have a maximum width threshold of 20 m, homogeneous regardless of the source: Wider objects are not hedges. The minimum length and interruption thresholds for entry are those of the source of the objects (see: Selection).
In case of overlays between the two data sources, the geometry of the hedge from the BDTopo® Vegetation Zone class is retained.

Treatments based on the shape of the polygon and on distance criteria make it possible, on the one hand, to limit duplicates of the same hedge due to differences between the two data sources and, on the other hand, to reconstruct the continuities. Clean-ups have made it possible to remove overlays with transport axes (road and rail network).

Finally, a skeletonization makes it possible to generate a linear object from the surface.

For the list of variables, see pages 180 and 181 of the document "BD TOPO version 3.0 content description": [https://geoservices.ign.fr/sites/default/files/2021-07/DC_BDTOPO_3-0.pdf]

**INFORMATION**: THE DATA GAME IS AVAILABLE IN THREE FORMATS (*.XLSX, *.CSV AND *.GPKG). THE NUMBER OF REGISTRATION IS IN THE ORDER OF: 11591

**定义**：
树篱轴线。
树篱指由树木、灌木、荆棘或枝条构成的天然屏障，用于界定或保护地块。

**数据遴选**：
该线性树篱图层由BDTopo®植被区图层中属性Nature="Hedge"（树篱）的面状树篱，与地籍图形登记册（Register Parcellaire Graphique，RPG）中的面状树篱合并后经骨架化处理得到。
• BDTopo®植被区图层的（面状）树篱以树冠边缘为采集边界，要求其宽度小于20米、长度大于25米，采集截断阈值为20米。具体可参考植被区类中Nature="Hedge"的定义。
• RPG的（面状）树篱以土地通行权范围为采集依据，建模树篱的树冠宽度需小于20米，最小长度需满足一定延伸性要求，采集截断阈值为5米。

**几何建模**：
以首个树木树冠至最后一个树木树冠的连线作为树篱轴线。
上述由两类数据源合并得到的树篱，统一设置最大宽度阈值为20米——宽度超出该阈值的对象均不视为树篱。数据入库的最小长度与中断阈值遵循对应数据源的要求（详见：数据遴选部分）。
若两类数据源存在几何重叠，则保留BDTopo®植被区类的树篱几何信息。
通过基于多边形形状与距离准则的处理流程，一方面可规避两类数据源差异导致的同一树篱重复要素，另一方面可重构树篱的空间连续性。此外，通过数据清理移除了与交通轴线（道路与铁路网）的重叠要素。
最终通过骨架化处理，将面状树篱转换为线性对象。

变量清单详见《BD TOPO 3.0版内容说明》文档第180、181页：[https://geoservices.ign.fr/sites/default/files/2021-07/DC_BDTOPO_3-0.pdf]

**说明**：本数据集提供三种格式（*.XLSX、*.CSV与*.GPKG），总记录数约为11591条。